Cool off on hot summer days at one of the park's two excellent swimming beaches. Swimming is permitted at Monsanto and Pim lakes only. No cans, glass bottles, coolers, fires, alcohol or pets are allowed at the beaches. Swim at your own risk.
A large shelter with picnic tables and a grill is located at Monsanto Lake and is available by reservation. There are also benches, a volleyball net, a change house and a vault toilet. Pim Lake and beach is smaller than Monsanto, but has benches, picnic tables, barbecue grills, a change house and a vault toilet
Scuba diving is permitted in Monsanto and Pim lakes. You must be certified and must be accompanied by another certified diver. You are required to display a marker indicating your location. Divers must check in and out at the park office.